JP2017180275A - Hermetic two-stage compressor and compressor system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hermetic two-stage compressor capable of avoiding enlargement of a size and increase of a weight, and increasing an oil holding amount in a housing, and a compressor system including the hermetic two-stage compressor.SOLUTION: A hermetic two-stage compressor includes: a housing 11 having an oil reservoir O1 at a lower part of its internal part; a rotary compressor 12 configured to compress refrigerant R inside the housing 11; a scroll compression unit 13 arranged above the rotary compressor 12 inside the housing 11, and configured to further compress refrigerant R discharged from the rotary compressor 12; and an oil pot 17 communicating with a position of the oil reservoir O1 and the internal part of the housing 11 above the position of the oil reservoir O1, and configured to store oil A and supply oil A to the internal part of the housing 11.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a hermetic two-stage compressor and a compressor system including the same.

  Conventionally, for example, a hermetic two-stage compressor that is used for refrigeration and air conditioning and includes a low-stage compression unit and a high-stage compression unit that are sealed in a housing is known. An example of such a hermetic two-stage compressor is disclosed in Patent Document 1.

  In the hermetic two-stage compressor of Patent Document 1, a rotary compressor is arranged as a low-stage side compression unit, a scroll compressor is arranged as a high-stage side compression unit, and the gas supplied into the housing is transferred by the rotary compressor. After compression, the compressed air is further compressed by a scroll compressor and discharged from the housing. The hermetic two-stage compressor is operated in a state where lubricating oil for the low-stage compression section and the high-stage compression section is held in the housing. In order to avoid a decrease in operating efficiency of the hermetic two-stage compressor, it is important to retain a sufficient amount of oil in the housing.

JP 2009-180107 A

Here, a part of the oil in the housing is discharged out of the housing together with the compressed gas. In a hermetic type two-stage compressor, an oil return pipe is known so that oil discharged outside the housing returns to the housing again. However, due to problems such as long system piping, the housing Sufficient oil cannot be returned to the inside, and the amount of oil in the housing may be insufficient. For this reason, it is conceivable to increase the amount of oil retained in the housing by increasing the internal volume of the housing, and to solve the problem of insufficient oil amount.
However, when compressing a gas such as carbon dioxide, for example, the inside of the housing has a very high pressure, so the pressure resistance performance of the housing needs to be increased. In this case, if the inner volume of the housing is increased in order to solve the shortage of oil in the housing, the thickness of the housing must be increased accordingly. As a result, problems such as an increase in the size of the hermetic two-stage compressor and an increase in weight occur.

  Therefore, the present invention provides a hermetic two-stage compressor capable of increasing the amount of oil retained in the housing while avoiding an increase in size and weight, and a compressor system including the same.

  A hermetic two-stage compressor according to a first aspect of the present invention includes a housing having an oil sump at a lower portion inside thereof, a low-stage compression portion that compresses gas inside the housing, and an inside of the housing. A high-stage compression unit that is disposed above the low-stage compression unit and further compresses the gas discharged from the low-stage compression unit, the position of the oil reservoir, and the position of the oil reservoir An oil pot that communicates with the interior of the housing at the top, stores oil, and supplies oil to the interior of the housing.

  In such a hermetic two-stage compressor, oil can be constantly supplied to the inside of the housing by providing an oil pot communicating with the inside of the housing. In addition, since the oil pot communicates with the interior of the housing above the oil reservoir, the pressure can be the same between the interior of the housing and the interior of the oil pot. Therefore, it is possible to keep the oil level in the oil pot and the level of the oil sump in the housing at the same level. For this reason, by adjusting the oil amount in the oil pot, the oil amount inside the housing can be easily adjusted, and the shortage of the oil amount inside the housing can be avoided.

  Further, the hermetic two-stage compressor according to the second aspect of the present invention is provided in the oil pot in the first aspect, and the oil pot and the position corresponding to the high-stage compression portion in the housing; May be further provided with an oil dropping part that allows oil from the higher stage compression part to be introduced into the oil pot.

By providing the oil dropping part at such a position, it becomes possible to introduce the oil used for lubrication in the high stage side compression part into the oil pot. Therefore, the amount of oil that flows out of the housing together with the gas discharged from the housing can be reduced, and a shortage of the amount of oil inside the housing can be further avoided.
Furthermore, the oil spill part is connected to the oil pot and can return the oil to the inside of the housing via the oil pot. For this reason, compared with the case where the oil dropping part is directly connected to the housing and the oil is returned directly from the oil dropping part to the inside of the housing, the oil is returned to the inside of the housing by the gas flow inside the housing. It can suppress that oil is wound up. Therefore, it is possible to avoid that the oil that has been wound up passes through the high-stage compression portion and is discharged outside the housing. As a result, it is possible to reduce the amount of oil circulation (OC%) in the system.

  Further, the hermetic two-stage compressor according to the third aspect of the present invention includes an oil separator that separates oil from the gas discharged from the high-stage-side compression section in the first or second aspect, and the oil An oil return unit may be further provided that connects the separator and the oil pot so that oil from the oil separator can be introduced into the oil pot.

By providing such an oil return part, the oil that is compressed by the high-stage compression part and discharged from the housing together with the gas discharged from the housing is returned to the oil pot via the oil separator and the oil return part. Therefore, a shortage of oil in the housing can be further avoided.
Further, the oil return portion is connected to the oil pot and can return oil to the inside of the housing via the oil pot. Therefore, compared with the case where the oil return part is directly connected to the housing and the oil is returned directly from the oil return part to the inside of the housing, the oil is returned to the inside of the housing by the gas flow inside the housing. It can suppress that oil is wound up. Therefore, it is possible to avoid that the oil that has been wound up passes through the high-stage compression portion and is discharged outside the housing. As a result, it is possible to reduce the amount of oil circulation (OC%) in the system.

  Further, the hermetic two-stage compressor according to the fourth aspect of the present invention includes a gas heat exchange unit that heats the gas (injection gas) injected into the housing by the heat of the oil pot in the third aspect. Furthermore, you may provide.

Since the gas compressed by the high-stage side compression section, discharged from the housing and introduced into the oil separator is at a high temperature, the oil contained in this gas is also at a high temperature. Therefore, the oil pot can be heated by introducing the oil at a high temperature from the oil separator to the oil pot through the oil return portion.
Here, by performing heat exchange between the heated oil pot and the gas directly injected into the housing (injection gas) by the gas heat exchanger, it is possible to inject the gas into the housing in a heated state. Become. Therefore, liquid refrigerant can be prevented from being injected due to insufficient heating, and the reliability of the compressor can be improved.

  Further, the hermetic two-stage compressor according to the fifth aspect of the present invention includes an accumulator that separates a liquid phase from the gas in the third or fourth aspect and supplies a gas phase to the low-stage compression unit. And an accumulator heat exchanging section that heats the accumulator with the heat of the oil pot.

Since the gas compressed by the high-stage side compression section, discharged from the housing and introduced into the oil separator is at a high temperature, the oil contained in this gas is also at a high temperature. Therefore, the oil pot can be heated by introducing the oil at a high temperature from the oil separator to the oil pot through the oil return portion.
Here, by performing heat exchange between the heated oil pot and the accumulator by the accumulator heat exchanging unit, it is possible to heat the gas in advance with the accumulator before supplying the gas to the lower stage compression unit It becomes. Therefore, inhalation of the liquid refrigerant can be suppressed, and the reliability of the compressor can be improved.

  In the hermetic two-stage compressor according to the sixth aspect of the present invention, the accumulator and the oil pot in the fifth aspect may be arranged adjacent to each other.

  By arranging the accumulator and the oil pot at such a position, a bracket for attaching the oil pot to the housing and a bracket for attaching the accumulator to the housing can be made common. Therefore, it becomes easy to manufacture the hermetic two-stage compressor and reduce the cost.

  A hermetic two-stage compressor according to a seventh aspect of the present invention is provided in the oil pot according to any one of the first to sixth aspects, and is connected to the position of the oil sump in the housing. A connecting pipe is provided, the inside of the oil pot communicates with the inside of the housing at the position of the oil sump, and a sensor mounting portion is provided on the outer peripheral surface of the connecting pipe for installing a temperature sensor for measuring oil temperature. It may be done.

  By providing the sensor mounting portion on the connecting pipe in this manner, the temperature sensor can be installed on the outer peripheral surface of the connecting pipe having a smaller thickness than the wall surface of the housing. Therefore, it is possible to measure the temperature of the oil in the oil reservoir by installing the temperature sensor at a position closer to the oil in the oil reservoir in the housing. Therefore, the measurement system of the temperature of the oil in the oil reservoir can be improved.

  Further, the hermetic two-stage compressor according to the eighth aspect of the present invention is provided in the oil pot according to any one of the first to seventh aspects, and the height of the oil level in the oil pot. You may further provide the liquid level sensor which measures this.

  By measuring the liquid level position in the oil pot with such a liquid level sensor, the liquid level position of the oil sump in the housing at the same level as the liquid level position in the oil pot is indirectly measured. be able to. Therefore, by adjusting the amount of oil in the oil pot based on the measurement result of the liquid level sensor, it is possible to easily adjust so that the amount of oil in the housing does not run short, and avoid shortage of oil in the housing. it can.

  The compressor system according to the ninth aspect of the present invention includes a plurality of hermetic two-stage compressors according to any one of the first to eighth aspects, and the oil in each of the hermetic two-stage compressors. And an oil equalizing pipe for connecting the pots.

In such a compressor system, it is possible to always supply oil from the oil pot to the inside of the housing by providing the above-described hermetic two-stage compressor, and by adjusting the amount of oil in the oil pot, Since the internal oil amount can be easily adjusted, the shortage of the oil amount inside the housing can be avoided.
Furthermore, oil can be delivered between the oil pots in the plurality of hermetic two-stage compressors by the oil equalizing pipe. Therefore, the shortage of the oil amount inside the housing can be solved in the entire compressor system, and the reliability of the compressor system can be improved.
Further, the oil equalizing pipe is connected to the oil pot, and oil can be supplied to the inside of the housing via the oil pot. For this reason, compared with the case where the oil leveling pipe is directly connected to the housing and the oil is supplied directly from the oil leveling pipe to the inside of the housing, the oil is supplied to the inside of the housing by the gas flow inside the housing. It can suppress that oil is wound up. Therefore, it is possible to avoid that the oil that has been wound up passes through the high-stage compression portion and is discharged outside the housing. As a result, it is possible to reduce the amount of oil circulation (OC%) in the system.

  According to the above-described hermetic two-stage compressor and compressor system, by providing the above oil pot, it is possible to increase the amount of oil retained in the housing while avoiding an increase in size and weight. It becomes possible.

1 is an overall schematic diagram illustrating a compressor system according to an embodiment of the present invention. It is a longitudinal section showing a closed type two-stage compressor of a compressor system concerning an embodiment of the present invention.

Hereinafter, the compressor system 1 in the embodiment of the present invention will be described.
As shown in FIG. 1, a compressor system 1 includes a plurality of hermetic two-stage compressors 2 (hereinafter referred to as two-stage compressors 2), and an oil equalizing pipe 3 that connects the two-stage compressors 2 to each other. I have.

  As shown in FIG. 2, each two-stage compressor 2 compresses a refrigerant R, which is a gas such as carbon dioxide. The two-stage compressor 2 includes a housing 11, a rotary compressor (low-stage compression section) 12 provided inside the housing 11, a scroll compressor (high-stage compression section) 13, an electric motor 14, and a rotary shaft 15, and an accumulator 16 and an oil pot 17 provided outside the housing 11.

  The housing 11 includes a cylindrical main body portion 21, and an upper lid portion 22 and a lower lid portion 23 that close the upper and lower openings of the main body portion 21. The housing 11 seals the internal space.

  The rotary shaft 15 is supported by an upper bearing 31 provided at the upper part inside the housing 11 and lower bearings 32A and 32B provided at the lower part inside the housing 11, and rotates around the axis X with respect to the housing 11. It can be rotated. A discharge cover 60 fixed to the fixed scroll 51 with bolts 70 is provided at the top of the scroll compressor 13, and the inside of the discharge cover 60 is sealed with respect to the internal space of the housing 11. Here, the internal space of the housing 11 is an intermediate pressure space MC, and the internal space of the discharge cover 60 is a discharge space DC.

  The electric motor 14 is disposed on the outer peripheral side of the rotary shaft 15 in the intermediate pressure space MC in the housing 11 and rotates the rotary shaft 15 about the axis X. That is, the electric motor 14 includes a rotor 38 fixed to the outer peripheral surface of the rotating shaft 15 and a stator 39 fixed to the inner peripheral surface of the main body 21 of the housing 11 so as to face the outer peripheral surface of the rotor 38 in the radial direction. And have. A power source (not shown) is connected to the electric motor 14, and the rotating shaft 15 is rotated by electric power from the power source.

  The rotary compressor 12 is disposed inside the housing 11 and below the electric motor 14 at a position adjacent to the lower lid portion 23. The rotary compressor 12 includes an eccentric shaft portion 41 provided on the rotary shaft 15, a piston rotor 42 fixed to the eccentric shaft portion 41 and rotated eccentrically with respect to the axis X as the rotary shaft 15 rotates, and a piston A compression chamber C1 for accommodating the rotor 42 is provided with a cylinder 44 formed therein.

  The cylinder 44 is formed with a suction hole 44a through which the refrigerant R can flow. A suction pipe 33 provided through the main body 21 of the housing 11 is connected to the suction hole 44 a, and the refrigerant R is supplied from the outside of the housing 11 through the suction pipe 33. Further, a discharge hole (not shown) is formed in the cylinder 44, and the refrigerant R compressed by the rotary compressor 12 is discharged from the discharge hole into the intermediate pressure space MC of the housing 11.

  Here, the lower bearings 32 </ b> A and 32 </ b> B are arranged so as to sandwich the rotary compressor 12 from above and below in the direction of the axis X, and are fixed to the cylinder 44 with bolts 48.

  Oil A is stored at the bottom of the housing 11, and an oil reservoir O1 is provided. The liquid level of the oil reservoir O1 when the oil A is initially sealed is located above the rotary compressor 12. As a result, the rotary compressor 12 is driven in the oil sump O1.

  The scroll compressor 13 is disposed above the electric motor 14 inside the housing 11. The scroll compressor 13 includes a fixed scroll 51 fixed to the upper bearing 31 and a turning scroll 57 disposed below the fixed scroll 51 and facing the fixed scroll 51.

  The fixed scroll 51 has an end plate 52 fixed to the upper surface of the upper bearing 31 and a fixed wrap 53 protruding downward from the end plate 52. A discharge hole 52a penetrating vertically is formed in the center portion of the end plate 52 (in the vicinity of the axis X).

  The orbiting scroll 57 is disposed so as to be sandwiched between the upper bearing 31 and the end plate 52 of the fixed scroll 51 in the direction of the axis X and protrudes upward from the end plate 58. And a swivel wrap 59.

  The end plate 58 is fixed to an eccentric shaft portion 56 provided at the upper end of the rotary shaft 15, and rotates eccentrically with respect to the axis X as the rotary shaft 15 rotates.

The swirl wrap 59 meshes with the fixed wrap 53 to form a compression chamber C <b> 2 that compresses the refrigerant R between the swirl wrap 59.
Here, the fixed scroll 51 is formed with a suction hole (not shown) through which the refrigerant R compressed by the rotary compressor 12 and discharged into the intermediate pressure space MC of the housing 11 is sucked into the compression chamber C2. The refrigerant R compressed in the compression chamber C2 passes through the discharge hole 52a of the fixed scroll 51, passes through the discharge space DC in the discharge cover 60, passes through the housing 11 and opens from the discharge pipe 34 provided to the discharge space DC. It is discharged to the outside of the housing 11.

  The accumulator 16 is disposed outside the housing 11 and is fixed to the outer peripheral surface of the main body 21 of the housing 11 via a bracket 37a. In the accumulator 16, the liquid phase is separated from the refrigerant R, and the gas phase of the refrigerant R is supplied to the rotary compressor 12 through the suction pipe 33.

  The oil pot 17 is disposed outside the housing 11 and is fixed to the outer peripheral surface of the main body 21 of the housing 11 via a bracket 37b. The oil pot 17 has a cylindrical pot main body 61, a pot upper lid 62 and a pot lower lid 63 provided to be detachable from the main body 21 while closing the upper and lower openings of the pot main body 61. It has. The oil pot 17 stores oil A therein to form an oil reservoir O2. The oil pot 17 may be provided with an oil supply source (not shown) that supplies the oil A from the outside of the compressor system 1.

  The oil pot 17 is provided with a lower connecting pipe 67 that connects the lower end portion of the pot lower lid portion 63 and the lower end portion of the lower lid portion 23 of the housing 11. The lower connecting pipe 67 is opened in the oil sump O2 in the lower part inside the oil pot 17 and in the oil sump O1 inside the housing 11, and below the liquid level of these oil sumps O1 and O2. Is arranged.

  A sensor mounting portion 69 is provided on the outer peripheral surface of the lower connection pipe 67 so that a temperature sensor 81 for measuring temperature can be detachably mounted. The sensor mounting portion 69 may be provided in the lower connection pipe 67 at a position close to the housing 11. The temperature sensor 81 indirectly measures the temperature of the oil A in the oil reservoir O <b> 1 in the housing 11 by measuring the temperature of the outer peripheral surface of the lower connecting pipe 67.

  Further, the oil pot 17 is provided with an upper connection pipe 68 that connects the upper end portion of the pot upper lid portion 62 and the main body portion 21 of the housing 11. The upper connecting pipe 68 opens to the upper part of the oil reservoir O2 inside the oil pot 17 and the intermediate pressure space MC above the oil reservoir O1 inside the housing 11.

  Here, in the present embodiment, the oil pot 17 is provided with an oil dropping pipe (oil dropping portion) 72 connected thereto. The oil dropping pipe 72 connects the upper end portion of the oil pot 17 and a position corresponding to the scroll compressor 13 in the housing 11 so that the oil A from the scroll compressor 13 can be introduced into the oil pot 17. Here, the upper bearing 31 is formed with a bearing flow passage 31 a that opens in the housing 11 at a position in the direction of the axis X where the orbiting scroll 57 is fixed to the eccentric shaft portion 56 through the radial direction. . Further, the housing 11 is formed with a drop pipe opening 36 that communicates the bearing flow path 31 a with the outside of the housing 11. The oil drop pipe 72 is connected to the housing 11 by being inserted into the bearing flow path 31 a and the drop pipe opening 36.

Furthermore, in this embodiment, the discharge pipe 34 is provided with an oil separator 71. The oil separator 71 separates the oil A from the refrigerant R discharged from the discharge pipe 34.
The oil pot 17 is provided with an oil return pipe (oil return portion) 73 that connects the oil separator 71 and the oil pot 17.
The oil return pipe 73 can introduce the oil A separated by the oil separator 71 into the oil pot 17. The oil return pipe 73 opens into the oil pot 17 above the liquid level of the oil reservoir O2 in the oil pot 17.

Further, in the present embodiment, the oil pot 17 is provided with a refrigerant heat exchanging portion (gas heat exchanging portion) 74 that heats the refrigerant R1 (injection refrigerant) injected into the housing 11 by the heat of the oil pot 17. . Here, the housing 11 is provided with an injection pipe 35 provided so as to penetrate inside and outside.
For example, the refrigerant heat exchange unit 74 circulates the fluid F between the wall surface of the oil pot 17 and the refrigerant supply source 75 connected to the injection pipe 35, thereby compressing the scroll from the oil pot 17 and the injection pipe 35. The refrigerant R1 injected into the machine 13 is heated.

  Furthermore, in the present embodiment, the oil pot 17 is provided with an accumulator heat exchanging portion 77 that heats the accumulator 16 by the heat of the oil pot 17. For example, the accumulator heat exchange unit 77 heats the accumulator 16 by circulating the fluid F between the wall surface of the oil pot 17 and the wall surface of the accumulator 16.

  Further, in the present embodiment, a liquid level sensor 82 capable of measuring the height position of the liquid level of the oil sump O2 in the oil pot 17 is provided on the wall surface of the oil pot 17. The liquid level sensor 82 has a pair of measuring units 82a and 82b provided on the wall surface of the oil pot 17 so as to be separated from each other in the vertical direction. The liquid level sensor 82 emits a signal when the liquid level position reaches the upper measurement unit 82a, and emits a signal when the liquid level position becomes lower than the lower measurement unit 82b. Thereby, it is possible to maintain the liquid level position of the oil A between the pair of measuring units 82a and 82b.

As shown in FIG. 1, the oil equalizing pipe 3 is connected to the wall surface of the oil pot 17 in each of the two-stage compressors 2 between a pair of measuring units 82 a and 82 b in the liquid level sensor 82. Open inside. The oil equalizing pipe 3 communicates the insides of the oil pots 17 of the adjacent two-stage compressor 2 with each other.
Here, the opening position of the oil equalizing pipe 3 is preferably located above the liquid level position of the oil reservoir O1 when the oil A is initially sealed in the oil pot 17.

  In the compressor system 1 of the present embodiment described above, the oil pot 17 communicating with the inside of the housing 11 of each two-stage compressor 2 is provided, so that the oil A is always supplied to the inside of the housing 11. Can do. Further, since the oil pot 17 communicates with the interior of the housing 11 above the oil reservoir O1, the liquid level position of the oil reservoir O2 in the oil pot 17 and the liquid level position of the oil reservoir O1 of the housing 11 are the same. It becomes possible to keep the level. For this reason, by adjusting the amount of oil A in the oil pot 17, the amount of oil A inside the housing 11 can be easily adjusted, and an insufficient amount of oil inside the housing 11 can be avoided.

  Therefore, the compressor system 1 is provided with the oil pot 17, so that it is not necessary to increase the size of the housing 11 in order to solve the shortage of oil. For this reason, it is not necessary to increase the thickness of the housing 11 accordingly. Therefore, it is possible to increase the amount of oil A retained in the housing 11 while avoiding an increase in size and weight of the two-stage compressor 2.

  Further, in the present embodiment, the upper connecting pipe 68 is opened in the intermediate pressure space MC in which the intermediate-pressure refrigerant R after being compressed by the rotary compressor 12 exists. For this reason, the oil A discharged from the rotary compressor 12 can be effectively flowed into the oil pot 17. Therefore, the refrigerant R can be supplied to the scroll compressor 13 with the amount of oil A in the refrigerant R reduced, and the amount of oil A in the refrigerant R discharged from the scroll compressor 13 can be reduced. it can. As a result, the amount of oil A retained in the housing 11 can be further increased.

  Further, by providing the oil dropping pipe 72 in the oil pot 17, it is possible to introduce the oil A used for lubrication by the scroll compressor 13 into the oil pot 17. Therefore, the amount of oil A that flows out of the housing 11 together with the refrigerant R discharged from the housing 11 through the discharge pipe 34 can be reduced, and a shortage of oil inside the housing 11 can be further avoided.

  Further, the oil dropping pipe 72 is connected to the oil pot 17, and the oil A can be returned from the oil dropping pipe 72 to the inside of the housing 11 through the oil pot 17. Therefore, when the oil A is returned to the inside of the housing 11 as compared with the case where the oil dropping pipe 72 is directly attached to the housing 11 and the oil A is returned to the inside of the housing 11, the refrigerant R inside the housing 11 The oil A returned to the inside of the housing 11 by the flow can be prevented from being rolled up. Therefore, it is possible to avoid the oil A that has been wound up from passing through the scroll compressor 13 and being discharged to the outside of the housing 11. As a result, it is possible to reduce the amount of oil circulation (OC%) in the system.

  Further, by providing the oil return pipe 73 in the oil pot 17, the oil A that is compressed by the scroll compressor 13 and flows out of the housing 11 together with the refrigerant R discharged from the housing 11 is supplied to the oil separator 71 and the oil return. It can be returned to the oil pot 17 via the pipe 73. For this reason, the shortage of the oil amount inside the housing 11 can be further avoided.

  Further, the oil A can be returned from the oil return pipe 73 to the inside of the housing 11 via the oil pot 17. For this reason, compared with the case where the oil return pipe 73 is directly attached to the housing 11 and the oil A is returned to the inside of the housing 11, when the oil A is returned from the oil pot 17 to the inside of the housing 11, The oil A that has been returned to the inside of the housing 11 by the flow of the refrigerant R can be prevented from being rolled up. Therefore, it is possible to reduce the amount of oil A discharged from the housing 11 to the outside and reduce the amount of oil circulation (OC%) in the system. Furthermore, since the oil pot 17 is thinner than the housing 11, the oil return pipe 73 can be easily installed. For this reason, it becomes possible to hold down manufacturing cost.

  The refrigerant R compressed by the scroll compressor 13 and discharged from the housing 11 and introduced into the oil separator 71 is at a high temperature. For this reason, the oil A contained in this refrigerant | coolant R is also high temperature. Therefore, the oil pot 17 can be heated by introducing the oil A having reached a high temperature from the oil separator 71 to the oil pot 17 through the oil return pipe 73.

  Therefore, the refrigerant heat exchange unit 74 heats the refrigerant R1 by exchanging heat between the heated oil pot 17 and the refrigerant R1 (injection refrigerant) injected into the housing 11 using, for example, the fluid F. Can be injected into the housing 11. Therefore, the liquid refrigerant can be prevented from being injected due to insufficient heating, and the reliability of the two-stage compressor 2 can be improved.

  Further, the heat is exchanged between the heated oil pot 17 and the accumulator 16 by, for example, the fluid F by the accumulator heat exchanging unit 77, so that the accumulator 16 preliminarily supplies the refrigerant R to the rotary compressor 12. In addition, the refrigerant R can be heated. Therefore, inhalation of the liquid refrigerant can be suppressed, and the reliability of the two-stage compressor 2 can be improved.

  Further, by providing the sensor attachment portion 69 on the lower connection pipe 67, the temperature sensor 81 can be installed on the outer peripheral surface of the lower connection pipe 67 having a smaller thickness than the wall surface of the housing 11. Therefore, the temperature sensor 81 is installed at a position closer to the oil A in the oil reservoir O1, and the temperature measurement by the temperature sensor 81 becomes possible. Therefore, the measurement system of the temperature of the oil A can be improved.

  Further, the liquid level of the oil reservoir O2 in the oil pot 17 is measured by the liquid level sensor 82, whereby the liquid level of the oil reservoir O1 of the housing 11 that is at the same level as the liquid level position in the oil pot 17 is measured. The position can be measured indirectly. Therefore, by adjusting the amount of oil A in the oil pot 17 based on the measurement result of the liquid level sensor 82, the amount of oil A inside the housing 11 can be easily adjusted, and the oil inside the housing 11 can be adjusted. Insufficient quantity can be avoided.

  Further, the oil leveling pipe 3 enables the oil A to be delivered between the oil pots 17 in the plurality of two-stage compressors 2. That is, when the amount of oil A in the oil pot 17 of one two-stage compressor 2 increases and the liquid level rises beyond the position of the oil leveling pipe 3, the other two oil leveling pipes 3 are connected. Oil A can be introduced toward the oil pot 17 in the stage compressor 2. Therefore, it is possible to avoid a shortage of oil in the oil pot 17 of any two-stage compressor 2 in the compressor system 1. As a result, it is possible to avoid a shortage of oil in the housing 11 of any two-stage compressor 2. Therefore, in the compressor system 1 as a whole, the shortage of oil in the housing 11 can be solved, and the reliability of the compressor system 1 can be improved.

  Further, the oil A can be supplied to the inside of the housing 11 via the oil pot 17 by the oil leveling pipe 3, so that the oil A is supplied to the inside of the housing 11 compared to the case where the oil leveling pipe 3 is directly provided in the housing 11. When this is done, the oil A supplied to the inside of the housing 11 can be prevented from being rolled up by the flow of the refrigerant R inside the housing 11. Therefore, it is possible to prevent the oil A that has been wound up from passing through the scroll compressor 13 and being discharged to the outside of the housing 11. As a result, it is possible to reduce the amount of oil circulation (OC%) in the system. Furthermore, since the oil pot 17 is thinner than the housing 11, the oil leveling pipe 3 can be easily installed. For this reason, it becomes possible to hold down manufacturing cost.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the configurations and combinations of the embodiments in the embodiments are examples, and the addition and omission of configurations are within the scope not departing from the gist of the present invention. , Substitutions, and other changes are possible. Further, the present invention is not limited by the embodiments, and is limited only by the scope of the claims.
For example, the oil pot 17 may be disposed adjacent to the accumulator 16. Thereby, the bracket 37b for attaching the oil pot 17 to the housing 11 and the bracket 37a for attaching the accumulator 16 to the housing 11 can be made common. Therefore, the manufacture of the two-stage compressor 2 can be facilitated and the cost can be reduced.

  Furthermore, the oil dropping pipe 72, the oil return pipe 73, the refrigerant heat exchanging section 74, the accumulator heat exchanging section 77, the sensor mounting section 69 of the temperature sensor 81, and the liquid level sensor 82 are not necessarily provided.

  Further, in the housing 11, the rotary compressor 12 is provided as a low-stage compressor, and the scroll compressor 13 is provided as a high-stage compressor. However, the present invention is not limited to this. For example, the scroll compressor 13 may be provided as a low-stage compressor, and the rotary compressor 12 may be used as a high-stage compressor. The scroll compressor 13 may be provided on both the low stage side and the high stage side, or the rotary compressor 12 may be provided on both the low stage side and the high stage side. Further, a compressor other than the scroll compressor 13 and the rotary compressor 12 may be provided.

DESCRIPTION OF SYMBOLS 1 ... Compressor system 2 ... Sealed two-stage compressor 3 ... Oil equalizing pipe 11 ... Housing 12 ... Rotary compressor (low stage side compression part)
13 ... Scroll compressor (high stage compression section)
DESCRIPTION OF SYMBOLS 14 ... Electric motor 15 ... Rotary shaft 16 ... Accumulator 17 ... Oil pot 21 ... Main-body part 22 ... Upper cover part 23 ... Lower cover part 31 ... Upper bearing 31a ... Bearing flow path 32A, 32B ... Lower bearing 33 ... Intake pipe 34 ... Discharge pipe 35 ... Injection pipe 36 ... Drop pipe opening 37a ... Bracket 37b ... Bracket 38 ... Rotor 39 ... Stator 41 ... Eccentric shaft part 42 ... Piston rotor 44 ... Cylinder 44a ... Suction hole 48 ... Bolt 51 ... Fixed scroll 52 ... End Plate 52a ... Discharge hole 53 ... Fixed wrap 56 ... Eccentric shaft portion 57 ... Swivel scroll 58 ... End plate 59 ... Swivel wrap 60 ... Discharge cover 61 ... Pot body 62 ... Pot upper lid 63 ... Pot lower lid 67 ... Lower connection Pipe 68 ... Upper connecting pipe 69 ... Sensor mounting part 70 ... Bolt 71 ... Oil separator 72 ... Oil draining pipe (oil dropping part)
73 ... Oil return pipe (oil return part)
74 ... Refrigerant heat exchange section (gas heat exchange section)
75 ... Refrigerant supply source 77 ... Accumulator heat exchanging part 81 ... Temperature sensor 82 ... Liquid level sensor 82a, 82b ... Measuring part C1 ... Compression chamber C2 ... Compression chamber MC ... Intermediate pressure space DC ... Discharge space O1 ... Oil reservoir O2 ... Oil Pool F ... Fluid R ... Refrigerant R1 ... Refrigerant A ... Oil X ... Axis

Claims (9)

A housing having a sump in the lower part of the interior;
A low-stage compression section for compressing gas inside the housing;
A high-stage compression section that is disposed above the low-stage compression section inside the housing and further compresses the gas discharged from the low-stage compression section;
An oil pot that communicates with the interior of the housing above the position of the oil reservoir and the position of the oil reservoir, stores oil, and supplies oil to the interior of the housing;
Hermetic two-stage compressor.   An oil drop provided in the oil pot, connecting the oil pot to a position corresponding to the high-stage compression section in the housing, and allowing oil from the high-stage compression section to be introduced into the oil pot. The hermetic two-stage compressor according to claim 1, further comprising a section. An oil separator that separates oil from the gas discharged from the high-stage compression section;
An oil return section that connects the oil separator and the oil pot, and allows oil from the oil separator to be introduced into the oil pot;
The hermetic two-stage compressor according to claim 1, further comprising:   The hermetic two-stage compressor according to claim 3, further comprising a gas heat exchange unit that heats the gas injected into the housing by the heat of the oil pot. An accumulator for separating the liquid phase from the gas and supplying the gas phase to the low-stage compression section;
An accumulator heat exchanger that heats the accumulator with the heat of the oil pot;
The hermetic two-stage compressor according to claim 3 or 4, further comprising:   The hermetic two-stage compressor according to claim 5, wherein the accumulator and the oil pot are disposed adjacent to each other. The oil pot is provided with a connecting pipe connected to the position of the oil reservoir in the housing, and the interior of the oil pot communicates with the interior of the housing at the position of the oil reservoir,
The hermetic two-stage compressor according to any one of claims 1 to 6, wherein a sensor mounting portion for installing a temperature sensor for measuring the temperature of oil is provided on an outer peripheral surface of the connection pipe.   The hermetic two-stage compressor according to any one of claims 1 to 7, further comprising a liquid level sensor that is provided in the oil pot and measures a height of a liquid level of oil in the oil pot. A plurality of hermetic two-stage compressors according to any one of claims 1 to 8,
An oil equalizing pipe connecting the oil pots in each of the hermetic two-stage compressors;
A compressor system further comprising:

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